Lens Array Module

ABSTRACT

There is disclosed a millimeter wave power source module which may include a plurality of submodules. Each submodule may include a further plurality of circuit devices. Each circuit device may have an input coupled to a corresponding receiving element and an output coupled to a corresponding radiating element. Each submodule may also include a heat spreader for removing heat from the plurality of circuit devices. A combination RF feed network and heat sink may include a waveguide horn to couple an RF input wave to the receiving elements on each of the plurality of submodules. The combination RF feed network and heat sink may also include a heat exchanger thermally coupled to the heat spreaders of each of the plurality of submodules.

NOTICE OF COPYRIGHTS AND TRADE DRESS

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. This patent document may showand/or describe matter which is or may become trade dress of the owner.The copyright and trade dress owner has no objection to the facsimilereproduction by anyone of the patent disclosure as it appears in thePatent and Trademark Office patent files or records, but otherwisereserves all copyright and trade dress rights whatsoever.

RELATED APPLICATION INFORMATION

This patent is related to a copending application, attorney docketnumber R009-P07238US, entitled “Modular MMW Source Component”.

BACKGROUND

1. Field

This disclosure relates to sources for millimeter wave (MMW) RF power,and to high power sources for W-band applications in particular.

2. Description of the Related Art

Sources of medium and high power MMW radiation can be applied incommunications systems and in directed energy weapons. While lowerfrequency MMW wave application can now be satisfied with solid-statesources, high power sources for the W-band (75 MHz to 110 MHz)traditionally incorporate tubes such as magnetrons or gyrotrons.However, such tubes are expensive, bulky, fragile, and require highvoltage electrical power. Thus MMW sources incorporating tubes are notreadily portable.

Semiconductor devices are now available for use as oscillators oramplifiers in the W-band, but the available power output from eachsemiconductor device may be limited to no more than a few watts. Thusmedium and high power solid state W-band sources may use quasi-opticalmethods that combine the power output from a large plurality ofsemiconductor devices within a waveguide or in free space. Approachesthat have been suggested for combining the power output from pluralsemiconductor devices include the reflect array amplifier described inU.S. Pat. No. 6,765,535, the grid array amplifier described in U.S. Pat.No. 6,559,724, and the lens array or tray amplifier described in U.S.Pat. No. 5,736,908.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a power source module.

FIG. 2 is an end view of a power source module.

FIG. 3A is a side view of a power source module.

FIG. 3B is a side view of a portion of a power source module.

FIG. 4 is a partial exploded view of a combined RF feed network and heatsink.

FIG. 5 is an end view of a modular power source.

FIG. 6 is a top view of a modular power source.

FIG. 7 is a perspective view of a power source module.

DETAILED DESCRIPTION

Throughout this description, the embodiments and examples shown shouldbe considered as exemplars, rather than limitations on the apparatus andmethods disclosed or claimed.

Description of Apparatus

Referring now to the block diagram of FIG. 1, an exemplary power sourcemodule 100 may include a plurality of submodules 140A-H, not all ofwhich are identified in FIG. 1. The submodules 140A-H may or may not beidentical. While eight submodules 140A-H are shown in this example, thepower source module 100 may include a greater or lesser number ofsubmodules. The number of submodules must be an integer and may be apower of two. Each submodule 140A-H may be comprised of a generallyplanar substrate supporting a plurality of circuit devices 160A-H. Whileeight circuit devices 160A-H are shown on submodule 140A in thisexample, each submodule 140A-H may include a greater or lesser number ofcircuit devices 160. The number of circuit devices per submodule must bean integer and may be a power of two. The number of circuit devices persubmodule may be less than, equal to, or greater than the number ofsubmodules.

Each circuit device 160A-H may include one or more of an amplitudeadjuster 162, a phase shifter 164 and an amplifier 166. The amplitudeadjuster may be a variable attenuator, a variable gain amplifier stagewithin or in addition to amplifier 166, or some other gain adjustingdevice. The amplitude adjuster 162, the phase shifter 164 and theamplifier 166, may be separate devices or components, or may becompleted or partially implemented in one or more monolithic microwaveintegrated circuits. The circuit devices 160A-H on any submodule 140A-Hmay be identical or may be different.

Each circuit device 160A-H may have an input coupled to a correspondingreceiving element and an output coupled to a corresponding radiatingelement. For example, receiving element 150A may be coupled to the inputof circuit element 160A, and the output of circuit element 160A may becoupled to radiating element 170A. Receiving element 150A and radiatingelement 170A may each be a flared notch antenna, a tapered slot antenna,a Vivaldi antenna, a dipole antenna, a Yagi-uda antenna, or any otherend-fire antenna element. Receiving element 150A and radiating element170A may be identical or may be different.

The power source module 100 may include a wavefront expander 120 toaccept an MMW input wavefront 110 and to provide an expanded MMWwavefront 130. The MMW input wavefront 110 may be coupled from awaveguide or other transmission medium. The wavefront expander 120,represented in the block diagram of FIG. 1 as a pyramidal horn, mayinclude a pyramidal horn, a parallel-plate horn, a waveguide powerdivider or other power divider, lenses, curved or flat reflectors, andcombinations of these and other elements. The expanded MMW wavefront 130may be a plane wave or other wavefront.

The expanded MMW wavefront 130 may be coupled to the receiving elements,such as receiving element 150A, on the submodules 140A-H. Each receivingelement may convert a portion of the energy of expanded MMW wavefront130 into a signal coupled to the input of a corresponding circuitdevice. Each circuit device may amplify or otherwise modify the inputsignal from the corresponding receiving element and provide an outputsignal to the corresponding radiating element. For example, receivingelement 150A may provide an input signal to circuit device 160A. Circuitdevice 160A may, in turn, provide an output signal to radiating element170A. Each radiating element may convert the output signal from thecorresponding circuit element into a radiated wavefront (not shown). Theradiated wavefronts from the plurality of radiating elements on theplurality of submodules may be spatially combined to provide an outputwavefront (not shown) that differs from the expanded wavefront 130 inamplitude, direction, or some other property. The spatially combinedoutput wavefront may be coupled into an output waveguide (not shown) orradiated into free space.

FIG. 2 is an end view of a power source module 200, which may be similarin architecture and function to power source module 100. A plurality ofsubmodules 240A-H may be stacked in parallel between heat sinkstructures 222 and 228, which may function to remove heat from thesubmodules 240A-H. The heat sink structures 222 and 228 may includeslots, kerfs, or other features (not shown) to align and support theplurality of submodules 240A-H. Each submodule may include a dielectricsubstrate 242 supporting a plurality of circuit devices, of whichcircuit device 260 is typical. The dielectric substrate 242 may befabricated of alumina, beryllia, aluminum nitride, or other dielectricmaterial suitable for use at the frequency of operation of the powersource module 200.

Each dielectric substrate 242 may support linear arrays of receivingelements and radiating elements coupled to and generally aligned withthe circuit devices such as circuit device 160. The receiving elementsand radiating elements may be constructed as metal films on one or bothsides of the dielectric substrate 242 and are thus not visible in FIG.2. The plurality of submodules may be stacked in parallel andappropriately spaced such that the plurality of radiating elements arelocated on a Cartesian X-Y grid, with the ends of the plurality ofradiating elements lying in a common plane. The spacing between thecolumns of elements (the center-to-center spacing of the submodules asshown in FIG. 2) may be λx, where λ is the frequency of operation of thepower source module 200 and x is a constant typically between 0.5 and1.0. The spacing between adjacent columns of elements may be exactlyequal to the nominal spacing of λx or may deviate from the nominalspacing by a tolerance. The tolerance may be ±λ/10 or some othertolerance. The constant x may be selected such that the nominal spacingbetween the columns of elements may between 0.5λ and 1.0λ.

The spacing between the rows of elements (the center-to-center spacingof the radiating elements on each submodule as shown in FIG. 2) may beλy, where λ is the frequency of operation of the power source module 200and y is a constant typically between 0.5 and 1.0. The spacing betweenadjacent rows of elements may be exactly equal to the nominal spacing ofλy or may deviate from the nominal spacing by a tolerance. The tolerancemay be ±λ/10 or some other tolerance. The constant y may be selectedsuch that the spacing between the rows of elements may between 0.5λ and1.0λ. The constants x and y may be equal or may be different.

Each submodule may also include a heat spreader 244 to conduct heat fromthe circuit devices to the heat sink structures 222 and 228. The heatspreader may be comprised of a metal material such as aluminum orcopper, or a thermally conductive ceramic material such as alumina,beryllia, or aluminum nitride. The heat spreader 244 may be the samematerial as the dielectric substrate 242 or another material. The heatspreader 244 may be bonded or otherwise attached to the dielectricsubstrate 242 with a heat conducting material. Similarly, the interfaces246 and 247 between the heat spreader 244 and the heat sink structures222 and 228 may be filled with a heat conducting material. Suitable heatconducting materials may include a thermally-conductive grease, athermally-conductive adhesive, a brazing material, or some otherthermally-conductive material.

The power source module 200 may include end caps on one or both sides,of which only end cap 280 is shown in FIG. 2. The end cap 280 mayinclude a metal plate 282 and may include a dielectric plate 284. Theposition of the end cap 280 and the thickness and dielectric constant ofdielectric plate 284 may be selected to create a fixed boundarycondition on an expanded wavefront (130 in FIG. 1, for example) coupledinto the submodules 240A-240H.

FIG. 3A is a side view of a power source module 300, which may besimilar to the power source module 200 of FIG. 2. The power sourcemodule 300 may contain a plurality of submodules stacked in parallel, ofwhich only submodule 340A is visible. Submodule 340A may include aplurality of circuit devices, of which circuit device 360A isrepresentative. Each circuit device may have an input coupled to areceiving element and an output coupled to a radiating element. Forexample, receiving element 350A may be coupled to the input of circuitdevice 360A, and the output of circuit device 360A may be coupled toradiating element 370A.

The edges of the submodules (i.e. the top and bottom edges as shown inFIG. 3A) not occupied by the receiving elements and the radiatingelements may be in thermal contact with metal structures 328 and 322.Metal structures 322, 328, and 324 may collectively form a combined heatsink and wavefront expander. The wavefront expander may accept an inputwavefront 310 from a waveguide or other transmission medium and form anexpanded wavefront 338 coupled to the plurality of receiving elements onthe plurality of submodules.

The wavefront expander may be comprised of two sections. The firstsection may be a waveguide power divider 380 that expands the inputwavefront along the axis normal to the page in FIG. 3A. Referring now toFIG. 4, the waveguide power divider 380 may be formed by channelsmachined into metal structure 324, as shown, or metal structure 322 orboth metal structures 322 and 324. The waveguide power divider mayaccept the input wavefront 310 and provide a uniaxially expandedintermediate wavefront 332.

Referring back to FIG. 3A, the second section of the wavefront expandermay be a parallel plate horn comprised of metal structures 322 and 328.The parallel plate horn may accept the uniaxially expended intermediatewavefront 332 from the waveguide power divider 380. The parallel platehorn may gradually expand the wavefront, as indicated by dashed lines334 and 336. The output of the parallel plate horn may be an expandedwavefront 338 coupled to the plurality of receiving elements on thesubmodules, of which receiving element 350A is representative. Theparallel plate horn may be specifically shaped to maintain a parallelplate mode. The expanded wavefront 338 may be a plane wave or otherwavefront.

Metal structures 322 and 328 may function as a heat exchanger to removeheat generated in the submodules such as submodule 340A. Metalstructures 322 and 328 may each include one or more heat exchangercoolant channels 390. Heat generated in the circuit devices on thesubmodules may be coupled to the metal structures 322 and 328 by heatspreaders incorporated in each submodule. This heat may be conductedthrough the metal structures 322 and 328, and then transferred to acoolant fluid flowing through the heat exchanger coolant channels 390.The coolant fluid may be gaseous or liquid. While the heat exchangercoolant channels are shown as simple circular openings in FIG. 3, thecoolant channels may include fins, vanes, posts and other structures.Such structures may be incorporated to increase the surface area exposedto the flowing coolant and/or to increase the turbulence of the coolantto improve the efficiency of heat transfer from the metal structures tothe coolant. Each metal structure 322 and 328 may have multiple coolantchannels, which may be disposed at any location where the thickness ofthe metal structure is sufficient.

Metal structures 324 and 328 may be a single continuous piece, or may beseparated by a dielectric slab 326. When the dielectric slab is present,metal structure 328 may be electrically isolated at DC and lowfrequencies from metal structures 324 and 322. When the dielectric slab326 is present metal structures 322 and 328 are DC isolated, and may beused as a DC feed network to provide DC electrical power to thesubmodules, such as submodule 340A. In this case, each submodule may beelectrically coupled to the metal structures 322 and 328.

When metal structures 324 and 328 are DC isolated by dielectric slab326, a standard RF choke groove 327 may be cut into either metalstructure 324 or 328. The use of such grooves is fairly common practicewhen joining waveguide flanges. The RF choke groove is locatedone-fourth of a wavelength (accounting for the dielectric constant ofthe dielectric slab 326) from the surface of the metal structure, and iscut one-fourth of a wavelength deep. The resultant effect is a one-halfwavelength shorted transmission line which acts as an RF short acrossthe discontinuity caused by dielectric slab 326. Thus the presence ofthe dielectric slab 326 does not effect propagation of the MMW wavefrontin the parallel plate horn formed by metal structures 322 and 328.

When the metal structures 322 and 328 are used as a DC feed network toprovide DC electrical power to the submodules, such as submodule 340A,end caps (not visible in FIG. 3) may still be used to bound thewavefronts (332, 334, 336, 338) within the wavefront expander. However,in this case, the end caps must be designed and disposed in a mannerthat does not create an electrical short between the metal structures322 and 328.

FIG. 3B is a side view of a portion of a power source module, which maybe similar to the power source module 300 of FIG. 3A. FIG. 3B shows asubmodule 341A and portions of metal structures 323 and 329 which mayfunction to remove heat from a plurality of submodules, of which onlysubmodule 341A is visible. Submodule 341A includes a plurality ofradiating elements, such as radiating element 371A, and a plurality ofreceiving elements such a receiving element 351A. In the example of FIG.3B, a center-to-center spacing of the plurality of receiving elementsmay be smaller than a center-to-center spacing of the plurality ofradiating elements, allowing a greater cross-sectional area for metalstructures 323 and 329 as compared to metal structures 322 and 328 ofFIG. 3A.

FIG. 5 is an end view of a modular MMW power source comprised of fourpower source modules 500A-D, which may be similar to power source module300 of FIG. 3. The four modules are juxtaposed to form a 2N×2M Cartesianarray of radiating elements, where N is the number of submodules permodule and M is the number of radiating elements per submodule. Thewidth 510 of each module, measured normal to the planes of thesubmodules, may be essentially equal to Nλx, where λ is the operatingfrequency of the power source and x is a constant typically between 0.5and 1.0. In this context, “essentially equal to” means exactly equal tothe nominal value of ±λx or deviating from the nominal value by no morethan an acceptable tolerance, which may be ±λ/10. In the event that thewidth of each module is exactly equal to Nλx, the modules may bedirectly abutted to maintain uniform spacing 520 essentially equal to λxbetween columns of radiating elements. In the event that the width ofeach module is slightly less than Nλx, shims or another spacingmechanism may be used to establish the correct spacing between adjacentmodules.

The height 530 of each submodule may be essentially equal to Mλy. Toallow room for the metal structures that conduct heat away from thesubmodules, the height 530 of each submodule may be essentially equal to(M+1)λy. In this case the spacing 540 between rows of radiating elementsmay be essentially equal to λy except at the boundaries between adjacentsubmodules, where the spacing 550 between radiating elements may beessentially equal to 2λy. Effectively, a single row of radiatingelements may be missing at the boundary between adjacent modules.

As used in the preceding paragraphs, height and width, and row andcolumn, are relative terms descriptive of the modular power source asshown in FIG. 5. These terms do not imply any absolute orientation ofthe modular power source.

The modular MMW power source may include end caps, similar to end cap280 of FIG. 2 but not shown in FIG. 5, to create appropriate boundaryconditions for the modules. The end caps may only be disposed on theoutside of the module MMW power source module (on the right and leftsides as shown in FIG. 5).

FIG. 6 is a side view of power source modules 600A and 600B, which maybe similar to power source module 300 and may be a portion of a modularpower source such as that shown in FIG. 5. The heat exchanger coolantchannel 690 may be coupled from power source module 600A to power sourcemodule 600B such that a coolant fluid may flow continuously through theadjacent power source modules. Alternatively, each power source module600A and 600B may have an independent coolant inlet and outlet, notshown. To improve the heat conduction from the submodules (not visiblein FIG. 6) to a heat exchanger coolant channel 690, each submodule 600A,600B may have a high thermal conductivity insert 695. The high thermalconductivity insert 695 may be a slab of a high thermal conductivitymaterial that is bonded into a recess machined into the metal structure628. The high thermal conductivity material may have a thermalconductivity substantially higher than the thermal conductivity of themetal structure 628. For example, the metal structure 628 may befabricated from copper to provide high electrical conductivity, and theinsert 695 may be pyrolytic graphite which has a thermal conductivity onone axis nearly four times that of copper.

FIG. 7 is a perspective view of a power source module 700, which may besimilar to power source module 300. Power source module 700 may includeprovisions, such as pins 796, for aligning and mating adjacent powersource modules in a modular power source such as that previously shownin FIG. 5. Portions of the metal structure, not required for thewavefront expander or DC feed network, may be removed to reduce weight,forming cavities such as cavity 798. Power source module 700 may includefeatures, such as slot 755, in the heat sink metal structures to holdand align the submodules. Power source module 700 may include features,such as the counterbore 792 and the mating O-ring 794 to seal the heatexchanger coolant channels 790 between adjacent power source modules ina modular power source such as that previously shown in FIG. 5.

Closing Comments

The foregoing is merely illustrative and not limiting, having beenpresented by way of example only. Although examples have been shown anddescribed, it will be apparent to those having ordinary skill in the artthat changes, modifications, and/or alterations may be made.

Although many of the examples presented herein involve specificcombinations of method acts or system elements, it should be understoodthat those acts and those elements may be combined in other ways toaccomplish the same objectives. With regard to flowcharts, additionaland fewer steps may be taken, and the steps as shown may be combined orfurther refined to achieve the methods described herein. Acts, elementsand features discussed only in connection with one embodiment are notintended to be excluded from a similar role in other embodiments.

For means-plus-function limitations recited in the claims, the means arenot intended to be limited to the means disclosed herein for performingthe recited function, but are intended to cover in scope any means,known now or later developed, for performing the recited function.

As used herein, “plurality” means two or more.

As used herein, a “set” of items may include one or more of such items.

As used herein, whether in the written description or the claims, theterms “comprising”, “including”, “carrying”, “having”, “containing”,“involving”, and the like are to be understood to be open-ended, i.e.,to mean including but not limited to. Only the transitional phrases“consisting of” and “consisting essentially of”, respectively, areclosed or semi-closed transitional phrases with respect to claims.

Use of ordinal terms such as “first”, “second”, “third”, etc., in theclaims to modify a claim element does not by itself connote anypriority, precedence, or order of one claim element over another or thetemporal order in which acts of a method are performed, but are usedmerely as labels to distinguish one claim element having a certain namefrom another element having a same name (but for use of the ordinalterm) to distinguish the claim elements.

As used herein, “and/or” means that the listed items are alternatives,but the alternatives also include any combination of the listed items.

1. A millimeter wave power source module, comprising N submodules, whereN is an integer greater than 1, each submodule comprising M circuitdevices, where M is an integer greater than 1, each circuit devicehaving an input and an output M receiving elements, each coupled to theinput of a corresponding one of the M circuit devices M radiatingelements, each coupled to the output of a corresponding one of the Mcircuit devices a heat spreader for removing heat from the M circuitdevices a combination RF feed network and heat sink comprising awavefront expander to receive an RF input wave, to expand the RF inputwave along at least one axis, and to couple the expanded RF input waveto the M receiving elements on each of the N submodules a heat exchangerthermally coupled to the heat spreaders of each of the N submodules. 2.The millimeter wave power source module of claim 1, wherein M and N arepowers of two.
 3. The millimeter wave power source module of claim 2,wherein M and N are equal.
 4. The millimeter wave power source module ofclaim 1, wherein the N submodules are stacked in parallel to provide aplanar array of N×M radiating elements.
 5. The millimeter wave powersource module of claim 4, wherein the N×M radiating elements aredisposed on a rectilinear X-Y grid with the spacing between adjacentpairs of radiating elements between 0.5λ and 1.0λ on each of the X and Yaxes, where λ is an operating frequency of the millimeter wave powersource module.
 6. The millimeter wave power source module of claim 5,wherein the overall dimensions of the millimeter wave power sourcemodule, measured along the X-Y grid are essentially equal to Nλx by Mλyor Nλx by (M+1)λy, wherein x and y are constants between 0.5 and 1.0. 7.The millimeter wave power source module of claim 4, wherein the moduleis adapted to be juxtaposed with a plurality of similar modules toprovide a modular array, wherein the radiating elements of the modulararray are disposed on a rectilinear X-Y grid with the spacing betweenadjacent grid points equal to λx on the X axis and λy on the Y axis,wherein λ is an operating frequency of the millimeter wave power sourcemodule and wherein x and y are constants between 0.5 and 1.0. no morethan one row or column of radiating elements is absent at the boundarybetween adjacent juxtaposed module.
 8. The millimeter wave power sourcemodule of claim 1, wherein each circuit device comprises at least one ofan amplifier, an amplitude adjuster, and a phase shifter.
 9. Themillimeter wave power source module of claim 1, wherein each receivingelement and each radiating element comprises a Vivaldi notch element.10. The millimeter wave power source module of claim 1, the combinationRF feed network and heat sink further comprising a waveguide powerdivider a parallel plate horn wherein the parallel plate horn expandsthe RF input wave along a first axis and the waveguide power dividerexpands the RF input wave along a second axis orthogonal to the firstaxis.
 11. The millimeter wave power source module of claim 1, thecombination RF feed network and heat sink further comprising at leastone insert of a high thermal conductivity material wherein thecombination RF feed network and heat sink is formed primarily from anelectrically conductive metal material and the thermal conductivity ofthe high thermal conductivity material is substantially higher than thethermal conductivity of the electrically conductive metal material. 12.The millimeter wave power source module of claim 11, wherein the highthermal conductivity material is pyrolytic graphite.
 13. The millimeterwave power source module of claim 1, the combination RF feed network andheat sink further comprising a DC power feed to the N submodules. 14.The millimeter wave power source module of claim 13, the combination RFfeed network and heat sink further comprising a first portion a secondportion DC-isolated from the first portion wherein the first portion andthe second portion conduct DC power to the N submodules.
 15. Themillimeter wave power source module of claim 14, the combination RF feednetwork and heat sink further comprising a dielectric plate disposedbetween the first portion and the second portion to provide DC isolationan RF choke groove cut into one of the first portion and the secondportion, the RF choke groove to provide an RF short between the firstportion and the second portion.
 16. The millimeter wave power sourcemodule of claim 1, wherein the combination RF feed network and heat sinkcouples a plane wave of millimeter wave radiation to the receivingelements on the N submodules.
 17. A millimeter wave power source module,comprising N submodules, where N is an integer greater than 1, eachsubmodule comprising M circuit devices, where M is an integer greaterthan 1, each circuit device having an input and an output M receivingelements, each coupled to the input of a corresponding one of the Mcircuit devices M radiating elements, each coupled to the output of acorresponding one of the M circuit devices a combination RF and DC feednetwork comprising a wavefront expander including a first portion and asecond portion DC-isolated from the first portion, the wavefrontexpander to receive an RF input wave, to expand the RF input wave alongat least one axis, and to couple the expanded RF input wave to the Mreceiving elements on each of the N submodules wherein the first portionand the second portion conduct DC power to the N submodules.
 18. Themillimeter wave power source module of claim 17, the combination RF andDC feed network further comprising a dielectric plate disposed betweenthe first portion and the second portion to provide DC isolation an RFchoke groove cut into one of the first portion and the second portion,the RF choke groove to provide an RF short between the first portion andthe second portion.
 19. The millimeter wave power source module of claim17, wherein the combination RF and DC feed network couples a plane waveof millimeter wave radiation to the receiving elements on the Nsubmodules.
 20. The millimeter wave power source module of claim 17,wherein M and N are equal powers of two.
 21. The millimeter wave powersource module of claim 17, wherein the N submodules are stacked inparallel to provide a planar array of N×M radiating elements.
 22. Themillimeter wave power source module of claim 21, wherein the N×Mradiating elements are disposed on a rectilinear X-Y grid with thespacing between adjacent pairs of radiating elements equal to λx on theX axis and λy on the Y axis, wherein X is an operating frequency of themillimeter wave power source module and wherein x and y are constantsbetween 0.5 and 1.0.
 23. The millimeter wave power source module ofclaim 22, wherein the overall dimensions of the millimeter wave powersource module, measured along the X-Y grid are essentially equal to Nλxby Mλy or Nλx by (M+1)λy.
 24. The millimeter wave power source module ofclaim 21, wherein the module is adapted to be juxtaposed with aplurality of similar modules to provide a modular array, wherein theradiating elements of the modular array are disposed on a rectilinearX-Y grid with the spacing between adjacent grid points equal to λx onthe X axis and λy on the Y axis, wherein λ is an operating frequency ofthe millimeter wave power source module and wherein x and y areconstants between 0.5 and 1.0 no more than one row or column ofradiating elements is absent at the boundary between adjacent juxtaposedmodule.
 25. The millimeter wave power source module of claim 17, whereineach circuit device comprises at least one of a power amplifier, anamplitude adjuster, and a phase shifter.
 26. The millimeter wave powersource module of claim 17, wherein each receiving element and eachradiating element comprises a Vivaldi notch element.
 27. The millimeterwave power source module of claim 17, the combination RF and DC feedfurther comprising a waveguide power divider a parallel plate hornwherein the parallel plate horn expands the RF input wave along a firstaxis and the waveguide power divider expands the RF input wave along asecond axis orthogonal to the first axis.
 28. A millimeter wave powersource array, comprising a plurality of juxtaposed modules, wherein eachmodule further comprises N submodules, where N is an integer greaterthan 1, each submodule comprising M circuit devices, where M is aninteger greater than 1, each circuit device having an input and anoutput M receiving elements, each coupled to the input of acorresponding one of the M circuit devices M radiating elements, eachcoupled to the output of a corresponding one of the M circuit devices aheat spreader for removing heat from the M circuit devices a combinationRF feed network and heat sink comprising a wavefront expander to receivean RF input wave, to expand the RF input wave along at least one axis,and to couple the expanded RF input wave to the M receiving elements oneach of the N submodules a heat exchanger thermally coupled to the heatspreaders of each of the N submodules.
 29. A millimeter wave powersource array, comprising a plurality of juxtaposed modules, wherein eachmodule further comprises N submodules, where N is an integer greaterthan 1, each submodule comprising M circuit devices, where M is aninteger greater than 1, each circuit device having an input and anoutput M receiving elements, each coupled to the input of acorresponding one of the M circuit devices M radiating elements, eachcoupled to the output of a corresponding one of the M circuit devices acombination RF and DC feed network comprising a wavefront expanderincluding a first portion and a second portion DC-isolated from thefirst portion, the wavefront expander to receive an RF input wave, toexpand the RF input wave along at least one axis, and to couple theexpanded RF input wave to the M receiving elements on each of the Nsubmodules wherein the first portion and the second portion conduct DCpower to the N submodules.
 30. A millimeter wave power source module,comprising N submodules, where N is an integer greater than 1, eachsubmodule comprising a linear array of M radiating elements a heatspreader for removing heat a combination RF feed network and heat sinkcomprising a wavefront expander to receive an RF input wave, to expandthe RF input wave along at least one axis, and to couple the expanded RFinput wave to the N submodules a heat exchanger thermally coupled to theheat spreaders of each of the N submodules.
 31. The millimeter wavepower source module of claim 30, wherein the N submodules are stacked inparallel to provide a planar array of N×M radiating elements.
 32. Themillimeter wave power source module of claim 31, wherein the millimeterwave power source module is adapted to be juxtaposed with a plurality ofsimilar modules to provide a modular array, wherein the radiatingelements of the modular array are disposed on a rectilinear X-Y gridwith the spacing between adjacent grid points equal to λx on the X axisand λy on the Y axis, wherein λ is an operating frequency of themillimeter wave power source module and wherein x and y are constantsbetween 0.5 and 1.0 no more than one row or column of radiating elementsis absent at the boundary between adjacent juxtaposed module.
 33. Amillimeter wave power source module, comprising N submodules, where N isan integer greater than 1, each submodule comprising a linear array of Mradiating elements a combination RF and DC feed network comprising awavefront expander including a first portion and a second portionDC-isolated from the first portion, the wavefront expander to receive anRF input wave, to expand the RF input wave along at least one axis, andto couple the expanded RF input wave to the N submodules wherein thefirst portion and the second portion conduct DC power to the Nsubmodules.
 34. The millimeter wave power source module of claim 33,wherein the N submodules are stacked in parallel to provide a planararray of N×M radiating elements.
 35. The millimeter wave power sourcemodule of claim 34, wherein the millimeter wave power source module isadapted to be juxtaposed with a plurality of similar modules to providea modular array, wherein the radiating elements of the modular array aredisposed on a rectilinear X-Y grid with the spacing between adjacentgrid points equal to λx on the X axis and λy on the Y axis, wherein λ isan operating frequency of the millimeter wave power source module andwherein x and y are constants between 0.5 and 1.0 no more than one rowor column of radiating elements is absent at the boundary betweenadjacent juxtaposed module.